I have a all stock 89 305 tbi and when my car idles it will raise to about 1,100 revs and then drops down to about 750 or so and it does it constantly up and down up and down and it will stop when I put it in gear. Do I have a problem or do I need a tune-up? If someone knos let me kno, thanks.

 

It sounds like a sensor is f'ed up. Is your MAP hooked up? Are the voltages correct?

 

i have the same problem when its really cold outside and my car has been sitting for a while.

 

Check for a vacuum leak somewhere.

 

yah vaccum leak most likely or map unhooked (vaccum leak + other issues with that).

 

Check your base timing and all vacuum lines. Look closely at the TBI gasket. That is a common source for leaks. It wouldn't hurt to pull the TBI unit and clean the funk out from around the IAC (and vacuum passages). Refer to Dimented24x7's IAC instructions posted towards the bottom of the "new to TBI sticky".